Balloon and analogous device.



P. C. Him/NL mmm@ Mm Amoeous musa. APPLICATION FSLED API?. 2|, W68. s, anted Apr. i915 5 BBETMEEET P. C. HEWITT.

EALLGGN AND ANALOGOUS DEVICE.

APPLICATION FILED APR. 2l. |908. v

Patentad Apr. 6, 915.

P. C. HEWITT.

BALLGUN AND ANALOGUUS DEVICE.

APPLICATION FlLED APR. 2l. 1908.

Patented Apr. 6, 219i 5.

5 SHEETS-BREST L .wmA M2M. H ONmTTmmW Nm h m m @i JZ WITNESSES ilu; all

EER. CCOJEB HEWTT, 0F RINGOOD MANOR, NEXT? JERSEY.

' IBALLOOBAND ANALGGOS DEVICE.

Specification of Letcrs Patent.

Application filed April 2l, 1908. Serial No. 4281.302.

T0 r/Z 'wh om.. it m @y concern Be itlmown that I, PETER Coorriu HEWETT, a citizen of flic United States, aud a resident of Ringwood lauor, lie coiiluy of Rassaic and Slate of New Jersey. ia's'e iuyeutecl certain new aufl us `il proveuieus Re latin@ ro lie iialogous Devices, of which "he "'ol is a speciiica*ou Aballoon.

'lu tlie prior are, the total pressures ou iie iieaii lieve iieeu reduced ariel lie i'ructures adapted for somewzet higher speeds, by fiecreusing the maximum cross-soutien for a gri ven *volume uili clue reg" rel for minimum iucrci'iso of surface und skin friction Uea'eli long riiese lines l= resul'reil iii elongate-:i srruclure. ille lrc..Vv cicls or boris i @e commonly forme@ ou lines of or coiirexcd cones round al; Lilie ends This iras rende/l to reduce the total pressure on llie head for a. strucure of given volume. bul: itv lias not reduced elle effeceive presse res ou ceraiii portions of lie uri'r aurl sui-.li devices liare uoy beer. marie Willi reference toilie support o the external pressure luf a minimum iuierual pressure, uur have 'they lbeen constructed with regaril to a minimum pressure per unir area,A

particularljiY ilie forward siu'faces which firstveugagc ille air. Qou'sequeully, when ppm-led ouljv oy a uuiiorui pressure ci gas, uiliiu ille envelop. certain portions-of lie surface may yield. so iliat #fue struclure may become (lei ,mired at cciiipara tively lou speeds u'liereas. if marl@ according to my invention, with lie area and shape uiade sue'u 'to properly clistribue the .external pressure. suoli local excess of stress would riot occur. `W icrc distortion or deformation is ouce initiated at the forward end or the bou'. the defer-ming pressure becomes progressiYelp7 greater per unit area because of ie more effective angle or" irnpingcg proporiouately, and

lie @reforming or dis# if Iruis occurs at high speeds, it may be Verf." dangerous in a variety of Ways.

A The speed -u'l'iicli may be allaiued before undesirable effects will be clereloped, can be increased lo a certain ex'reub v ing 'the structural strength or pressure7 and may avail sucli expeflieuts, out eue of the t my invention 'is to iucreuse'lie ell'eczi f any given internal pressure f o. araiiable for supLcr; ol rire surface so lier the surface will withstand the pressure lu-c to a greater speed. by reason of the pressure being substariliallj; uniform per unit area. l accomplish. liif by proporioniug me arca aud sliapc of 'the surfaces of the licaci so thai; the pressure ou any one )ortiou of the ieceiug'surface shall lie as nearly equal that ou any other portion as may be desired, aud preferably sliail nowhere exceed a periuissible velue per uuii area. "',Vliere lie internal supporr is afforded lijJ u gas uiiiler pressure permissible 'ralue c" 1' mined liv rire. streugili of the irrati- "f one of iic most practical :mplicatiovm iuxciiiioii ifiolres supia'uiiu;r a given ex* 'teruai pressure liv a minimum internal pressure of the gas in oriler io keep iioivri lie leulqaig'e, TWilli iiesc 'olriecls in View, tlie lcugli. maximum cross-s lion, arul ratio o decrease of' adiaccntcross-sections of' lic slructurc are (leicriuiiuil lijf ilie exl'eiit lo which i'lie reactieve. mul ell'ceigirc pressures par unit arca must lic clislriliuferi for llie liy considering ille problem from vthe sanclpoint oi" permissible pressure per uuii. arca, iusrcail ol1 'lroui lie sianflpoiu of iuiuiiuiuu total resislmire. ami liv suitably7 ilislriiiuliug the ueail ressurc bj.' suitably proporioiiing; ilie area ami sliape oi' the sui-laces. l iu- `crease the speerl at which structure of lie applied either iu die (lireciiou or isluli/f iurposc iu View. The imporraul fact lialCG ing a given supporting strength in the best possible way, so that the surfaces may he able to withstand as high a speed as possible, or in the direction of getting the. least supporting strength necessary for a given speed to be attained.

I contemplate special areas and contours for the moving bony as a whole, and espe cially for the foiwvardly directed surface@ or head jiiortion. its the matter ol' pressure per unit area on the head portion is oi great importa-nce, regardless of what may be the shape of the-body portion, the head may be considered separately, assuming as lo tln` body portion only that it has a cross-section of a given ar \a. and a fairly regular ontline.

The airpiercing portion'of the l'm'wardly projecting member or head. particularly portions thereof nearest the apex, are prei'- erably of sulliciently regular cross-section so that the lateral components ol' the head resi stance are practically balanced. This mini mixes any tendency to lateral bending or whipping out of alinen'nmt. Preferablythe axis of the head is arranged inalinement with the center ol' resistance..

The pressnre'on an;Y unit area n'iay be further decreased for a given length by giving thellireailI ,a longitudinal contour such that the work of displacing the Huid medium is not concentrated upon the tip or extreme forward portion. 'l`o this end l prefer to 'make the longilaidinal contour such that the! air is displaced out ol' the path of movement ofthe balloon, as if by the action of constaniy/force per unit area, the head pressure being distributed .with approximate uniformity over the forward portion of the deflect-ing surfaces. This is an improi ement, independently of Whether the head be short or long, or the pressure per unit area, correspondingly large or small. lhelongitudinal taper of the head necessary to ac complish this does not depart mu`ch from that of converging straight lines as in a cone. ln most cases the departure from such contour, if any, should loe in the direction of longitudinally concaving the surface thereof, as by thinning or elongating-l the forward end or by swelling the diameter of the base. A cone of any pitch Will start v the air from a state of rest at the tip of the cone and the diverging sides thereof will move the air the distance necessary to permit the passage of the moving body, and to that extent, any cone or concaved cone is preferable to a longitudinally convexed formation. My invention thus contemplates` increasing the effectiveness of the available internal. pressure or supporting strength by utilization of three factors; namely, increase of dellecting surfacegdecrease of deflecting angle; and uniform distribution of the effort-over the deflecting area. One of these ,factors may bc given more prominence than the other, but preferably all are conjointl y utilized to prodnccsuch approximation of uniform distribution of head pressure as may be necessary to effect the desired de- -creaseof distorting ell'ort on any given portion of the area. In general, however, the length of the head will be greater aild the pitch of the del'lecting surfaces smaller, proportionally as the high speed limit inrreasd, but in practice, elongation involves relatire decrease of crosssection and the 'lengthening or thinning down toward the lgreater on those portions ofthe arc which are distant from the tip. A comparatively slight inward movement of the walls at this region of greater diameter will eifect a rel, ati vely great decrease in the volume of thev gas, and in the dellecting angle of the surfaces. Thiswill tend to maintain the internal pressure and at the same time to de` crease the elective external pressure at that point, and both changes will tend to maintain the shape of the air piercing apex for a. considerable time, even in the case of a bad lealr.

it is undesirable to move the air at higher velocities and to radial distances greater w" than necessary to permit. he passage of the main body of the balloon. 'l'hc air piercing member will do ,this if too blunt for the spec/l attained, even though it be, formed as `a cone or as a longitudinally concaved cone, and, one parl. of my invention involves forming the gas envelop or other moving boi. y from the base el' the cone to the plane of maximum diameter in proper correlation to the velocities imparted to the air by the head, so that the air will lose its energy and reach a. state of rest when it has moved ontwardly a distance equal to the maximum radius of the moving body. Desirable longi tudinal contours for this part of the surface, where the airis losing its radial velocity and coming to a state of rest,depart but little from the arcs of circles of large radius having lthe divergent surfaces of the cone approximately tangent thereto. vB y this construction and proportion, the air from a state of rest is moved o11t\\'ardly, and energy delivered to it-proportional to the length from the tip, and allowed gradually to come te a sta te of rest by the time it reaches the;

Ci (i fil plan@ o' inninnu'n Crosaseoion the uiloocly. when 'oeoil ia :woord- .wil always Hiv-fer Speed.

Aiein aliovo loil 'for vliioli lio iwf l.

is :ind contours of the lgiofl rfforwnzl-ly of its ma importo-iii; no El ziborloofl f "iol oispln-coineiif. 1 Jn@ bou Lorofl by the invul-(l 'nioveinon and '.nuro of alle air usii in upon lle Stern. It 4is important. ill iie stern or iiil bo giron suoli simpa 'that lio oir roving inward. shrill press io surface of' tlio mii, so tlm n iii@ bou. or 111:13' lie inurl@ Sinn-. li iliig ilusion flic b::lloon requiw:` r. sir ufuizil,ooinpriwsion member. iii@ imm-nul orcssurf oi lli@ gras from lion' io Sorn boing suiiiciont to rainsfvr lmrl; to lie oww ilu. vnorgy rwiorml :ii clio storn.

v ln .lli-:f i'roi'ri'ail omlwlimrnt ol niv iu- -:oii''ion *ilu from :zml rmi' portion:u air(l equal :nul Syiuuiotriifiil willi rosgwri' to :i contrai irzinfnorse plinio ol inufinuun (lininoor :mii i'lio longiiucliuiil Conour approxi* mno# Fini of* two von( ioiniicl lino@ to buse in u boil); to Lion Following llilx nrw of cirolos im 'inf ilu? olrx iif.Vx roms :is tungons. ilu iuflii o? i wim' 'ilario ilu rzirlius oi iluj lingo oi 'l uiiur @ouml Lo thro-i. or i'four i of (iio sono will prow A @mira The ratiosy of longi'ii io clinnieiers iiro floiorminoflbv lic porniissiliio iniornzil oressuri of lio lux :mil li); ilu maximum socal to be ziiiuinotl. sul)- ifc' to iii@ liniiiuiiong iniposorl in' otlior practical roquiremons.

A lizr mos'r p zuiirzii purpoSos. (lie 'li1-,irnl)lo doiioffiing :ingles for tlw foi-wr fl dollootino' surfaces iiix Wiliin roi-tuin volumi-:rfiwir nui-rou' limils for all speoflS :mil :ill siziw ol` ifi Cirolos lieiup; prui'orballoon and for uil permissible inernzil presi of gais. ilio vino; in friction by use i for lower )oeils pfzicioui valira lirin the or gars loss or envelop i ooconozs possibi@ when tlm lion' roziinocl #for tiiolouor ille internal pressure cle- :frmisoil zorrcsioiulingly. Hence, ,l prefer in; uso pruuiozill-v lio Sonn* pitch of clcilori'- ino' Mirino, z z: wiilo rango of Si'icofl. For zinco olio lio oruolicul ons@ of; :i balloon rouiziiuii si, giron foiunio of gus, :idillio-(i lo be ilriion :u1 :i (luiinio spoed. Say (30 nulos :in liour. unil compare the lioricl rosistances i'or carving proportions oi: bow, the radii mi iong'lis varying' in lio ratiorooiiired ifm-.consimili Yoimno. ll'rit-li a @one radius oi speeds l?) fooi mul long'li of 1,33 feet, fille piicli is siliori, i in i0. The actual values for an onx'e pimli, compared with the r volume but lues for other cones of equal l i i :i iiiilcii of l in S, l. in

res poeti so ly. l.

und l in fi., sliovf clearly the narrow Soins nniiis of pruoticziily desirable pitch.

ous Jlios mentioned nay oo limi from tlio oiiowing approiinzio values given in Yyou iii iuriiiers.

i703? the pitch of l in l0. the total head r-'ei' uncrmy.y 509 pounds. or about i of :i iioiuul por square foot of deleoting urea, mui uoou 300 pounds oli this is skin frio tion; for l in Sy the. total is about FAO l pound per square foot.y and 171i i ounaa or l 52j, the

pounds of ii skin friction; for l in to'iii o 12S() pounfsQ or alout iii poundsfpor Squziro `foot.y sind onlj,7 i250 pounds oi' it iS skin friction; while for l in -Li'tlie total 2800 pounds:` or about pounds per square foot. und 225 pouncls of it is skin friction. The corresponding; liorSe-powors oxiiencloil :it ilio loon' in overcoming flic liozul resist-zinco for cones of' rho olir ratios menionod are; something like 8G borso-powor. 100 li i'se-po\rei^. Q00 horse-power. unil -Lv'l liorSQ-power. rosipecioly.

l limo proriouly poinefl out. tlm liozul prosmru (luv io (lvm-Unio rouciion ai ill@ liou muy lio in largo part rocori'iml ui ,ioss is @on ilona insoweit is rleSii-olilo io rocluco liao iuer #o for may lio within lunis, und uiili fluo regard to Safe iiozirl pre-.

SurQS por un'ic nrw. ln the partir-ulm' ons@ :ilioro Ponsidorvfl. inrroasing the iiitfli muws the total liezul resistono? :incl liors-"o-pon'or requiroii. :is well :1S tlio Drossure por square foot-io inmenso in iupicl ratio. while tile part oi the. hemd resistono@ duo to Skin frioion cleoirezwosy Slowly. sind in actul idraulico inermi@ of piirli iotlocreziSf "clio longltl; unrl skin *friction Slioulil not be carried lwfonil the point whcro the inc-rowing head prosf sure becomes excessive. For sixty miles perhour, this is obviously somewhere between the proportions of l in 8 and l in 4.

The values for other speeds differ from the aboi'e approximately as the square of the speed, but with due allowance for this and with due regard for the desirable quali ties of rigidity of structure and convenience in maneuvering, anchorage7 etc., l have found that for all practically desirable speeds, sizes, and permissible internal pres! sure of gas, the air deflecting porti ons of the bow should have a ratio of radius to length lying between the above ratios and prefer ably between 1 in 5 and 1 in 7, the specific ratio of 1 in 5.5 being more desirable for most purposes, though for especially high speeds thelesser angle of 1 in G to 1 in 7 may be found preferable. lVheie the above considered cones are joined with tail portions consisting of syinnietricall.,v arranged cones of similar volume, so that the dynamic loss at'the bow is partly recovered at the stern. the 100 hoi'se-i'iower required for the in S cone reduces to about :rhorse-power for the complete, double. conc device of the saine pitch, while the Q horse-power required for the l in 5l cone reduced to about 75 horse-power for the double cone. it will be understood 'that `the horse-powers in each case are approximations of the net applied horse-power required to drive the i double cone envelop at (3() miles per hour.

The pitch of the cone being as above.. the length thereof in any particular case will depend upon the desired volume and lifting capacity of the gas bag. having due regard for the fact that the body portion should be approximately circular in cross-section and in longitudinal section should follow substantially the lines of circles having the' straight line elements of the cone tangent thereto at its base. As l have explained, the rear of the cone and the exact curvature of 'this body portion are not so important as the matter of pitch of the forward"detlecting portionbut in general'it may be said th'at the longitudinal curvature of the body portion should be ot a radius somewhere between 2 and 5 times the diameter of the base of the cone. device of this type will be self-sustaining against the air pressure at speeds ot sixty or more miles an hour. without any compression member other than gas al au internal pressure. sueh as is quite perl missible with material now obtainable in the market, The envelop requires only^a suitable suspension system for distributing the weight of the motor. propellers. etc.. eonstitilting the load. 'Vlie suspension system may comprise a truss for distributing the .load and the propeller pull lengthwise of the gas bag. and if desired. such a truss may extend to and form a stay for the points zit/bow and stern., Such a truss. however'fmust becomparatively light, and the gas envelop is preferably designed so as to b'e practically seltsustaining against head pressure, entirely independently of any such truss.

For minimum internal gas pressure or its converse, maximum speeds attainable with a given permissible internal pressure, the stern should be so shaped that the maximum pressure required to be supported by any portion thereof, will be at least as small` as any pressure to be supported by any portion of the bow. The use of a gas as an internal compression member is ofv'great advantage, since it is t'a r lighter than any possible wood or metal compression member that could be employed. lYhere tht` extreme end is very slender. it may be stayed -with supports or battens of wood. metal, whale bone. or other` wise, or it may be formed of fiber board or of cork. and it may consist-of a frame work suitably covered. or it may be made solid.

Another feature ot in'y ii'ivention involves a pplying the necessary power to the envelop through such connections that the stresses will be properly distributed and with suoli relative arrangenientoil parts that the center of effort will not be too far from the eenter of resistance. i

The use of an internal gas pressure greater than the static -1.iressure, increases the ability of the envelop to withstand pinching in or lateral pressure, and renders possible the sharper convergence of the suspension members which carry the load. This makes it practicable to locate the load quite close to-the envelop. A concentrated load, especially. when carried close to a relatively long envelop, makes itdesirable to employ .i relatively rigid girder or truss to receive the load and distribute it along a considerable portion of the length of the envelop. This is especially practicable where the truss is close to the envelop and the envelop itself is of greatlength asrcoinpared with its diameter.v rl`he tension members for the truss may depend from a netting or other saddle or series of saddles extending over the top of the gas'bag, but one feature of my invention especially concerns i specific suspension arrangement consisting o tl fabric sewed dii-eetl;v to the gas bag or to a longitudinal flap or pocket formed or cured to the gas bag. lf desired, the pocket may contain a longitudinal batten to insure a more ininutely uniform distril'iution'of the load along the line of attachment to the gas bag.

Preferably. the truss conforms to the contour of the gas bag Sufliciently so that.the suspei'iding fabric may inclose part or all of the truss without causing the general een lio tour of. the structure to depart inueh from 4 the regularity of curvature hereinbeiore/intruss, the win'dage is 'greatly decreased.

Hier f ausm msantz s conn fion to ha i'momousl Kaution concerns or the propehmmm @Gutenbmu jt necessa'lly be uw the unprovezmd 1f wimgmm frfmssts 'm di; ;::.LUQ:' heren' tive diagram indicating various proportions for the gas baO'. Fig. lll is a partial, transv verse, sectional View. illustrating means' for suspending the truss from the gas bag. Fig. 15 is a partial sectional View o'f the apparatus shown in Fig. 1-t and illustrates means for securing the separate portions of the supporting hammock together and for securing the hammock to the truss.

The ballooncomprises a gas bag 1, truss 2, motor 3, transverse supports 4;, 5, for propellers v6, 7; forward and aft rudders 8, 9, respectively, and forward and aft balancing planes or horizontal rudders 10, 11 respecti vely.

The form of gas bag shown in ndl figures, except 9 and 13, is one in which the converging portions 12, 13 are approximately conical., having a pitch between 1 in 55 and'l in the pitch being reckoned as the ali'ective pitch of the surface acting as a wedge and this is measured by the angle of the snrface with respect to the direction of movement, lather than by the angle at which the opposite portions of the exterior surface intersect at the apex. The central portion 10iis formed on a circle of large radius hai'- ing straight line elements of concs 12, 13 as tangents. The pitch of the cones and the curvature of the body portion are shown as symmetrical with respect to the t'ansrerse plane of maximum cross-sectionY rl`he pitch and curvature and the total length of the structure with respect to its diameter are all predetermined Awith respect to a high speed to be attained and the proportions shown 'are approximately such as are suitable for speeds of 5() or (i0 miles an hour with an internal gas pressure such as is permissible in connection with gas bag materials now well known in the art. Being designed for high sp eds, it is of properproportions for any lower speed.

AThe truss Z is extremely light in construe` tion and is broadened out laterally toward the center, and it is also deepened at 1i, and

4is utilized as the car or load carrying platform. In all of the figures thel truss is shown as extending throughout the load carrying portion of the length of the gas bag, and in all figures, except Fig. 12,'it is sho-rn as extending to the tip, both `for\\'ard and aft, so as to forni a stay for this portioirof thil gas bag. This is not essential because the' internal pressure olf the gas is alone sollicient to sustain the tip.

lVithin the gas bag an innc'r enrclop or balloonet stayed in position by ronnwtion with the gas bag at 1G. The lower end l? of thisrenrelop, is connected to a blower or other desired means for maintaining pressureJ therein, diagrammatically indicated at 18,' Fig. l. 'l`he outer envelop l, being pre viously filled with gas and closed against vescape thereof, th'.` internal pressure may be regulated by the pressure applied in 15. The latter may contain gas or air, preferably air. lf desired, this inner bag 15 ma be contained within a second bag 19, of approxiu'iately the same dimensions. In such case the total lifting power or levitation of the balloon may be varied by using the space between envelops 15 and 19 for gas, while compressed air only is supplied in 15. Similarly, if desired, gas may be contained in 15 and the space betweenv 15 and 1f) .may be supplied with the compressed air from the blower. By such means, a desired internal pressure may be maintained wit-hin the gas bag sutlicient to 'support the delecting surfaces against head resistance and' also to maintain an approximately circular cross-sectional contour for the gas bag under stress of the load.

The truss is shown as suspended by a slnirply converging fabric 19, 20, secured to the lag along the seams 2l, 22, which may be reinfcmzcd or stittened by longitudinal battons as indicated at 23, 24, in Figs.

2 and 6, whichtend to distribute the stress of the load uniformly.

' ln Figs. 3, Lt, and 12, the fabric is shown as completely closingin the main portions of the truss and the deeper central portion of the truss 14 is shown as closed in by walls 25, 26 and bottom 27. rlhey may be of fabric, though in certain cases part or all of the bottom may be of eelluloid, glass or other transparent material. or the fabric may be providedwith suitably located winy dows 28, 29, 30. The truss is Alocated close to the gas bag, and is preferably shaped to 'conform to the longitudinally curved ,con-

tour thereof, so that the complete closing in by the fabric walls `does not greatly vary the 'symmetry of balance of the device when driven through the air. The car and load platform are substantially comprised within the central portion of the truss and the above described fabric walls. The exhaust of explosive motor 3 discharges through an exterior outlet' 30, preferably rearwardly directed and located at a point aft of the point of greatest cross-section. rl`he heat of the exhaust may be utilized in any desired way to raise or maintain the'tcmperatuie of the gas, as by arranging a portion of the exhaust conduit or a branch therefrom nearl iao Ultim f he t treme up mim T! util des lle 'uci-11i' ore corresponda;

.f5 ifm h lof. l

min speed i the :den

i) be Served by ports bint .ibo/v mi the re a rearward 12u gen Hwang 111g 'the the m required for this member.

ICO

In actual practice, itis extremely difficult to get the pitches, areas, and effective draft of the two propellers precisely the same. lVlhen the draft is unequal, the rudder surface necessary to correct the inequality may be considerable, and, moreover, unless the correction is made by means of vertical. rudders forming a horizontally acting dynamic couple, designed in accordance with the principles just described for the vertically acting dynamic couple, the effect will be to cause the balloon to drift to one side or the other, similarly to the up or down drift previously ref-erred to.

The location of the vertical rudders so that they may be used for 'this purpose, constitutes one feature of my invention, but I prefer to minimize the rudder effort necessary for this purpose by insuring equal -loads. on the propellers, and I do this by use of the differential gear between the driving` shaft and the sections of the propeller shafts, which causes the rotating effort or load on each to be the same, and hence their propelling effects as near equal as possible.

In order to construct successful balloons havinga relatively long gas bag adapted for high speeds, it is desirable to distribute the load longitudinally of the envelop in approximate proportion to the displacement and lifting power of the envelop at or near the cross-section where each portion of the load is found, so as to lessen the supporting strain on various portions of the truss and thereby lessen the massivencss and weight It is necessary to lump various portions of the load more or less, but this may be donc with such -due regardfor proportional distifibution of the lumps with respect to the lifting power that the total static balance with respect to the center of lift of the gas bag will be symmetrica and undisturbed.

' .In Fig. 1l I have indicated'by a. graphic diagram the manner in which this may be done. In this diagram, the projected longitudinal values-for weights of cloth and of frame and for total lift of the gas, as well as for net lift obtained by subtracting one from the other, are indicated in table Il. The distributionof weights of rudders, propellers, motor, etc, are projected at V. These weights multiplied respectively by the distances'of their effective leverages are indicated at W'. The center vand estimated amount ofl added weight. including what might be called the transient load, are indicated at X. vvThe dynamic' tilting effects due to the location. of the propeller below the center of resistance are indicated for speeds of 10, 30, and 60 miles .in hour in table Y. The balancing and correcting effects of the dynamic couple formed by th- Mulders l0 and 11 are worked out for the same speeds and for opposite the pressure will increase with the angular adjustments rep-A resented by pitches of lin G and l in 14,

and are indicated in table Z. Between the tables Y and Z are the specifications for location, area, etc., of said. balancing planes l0, l1. The power consumed in maintaining thedynamic balance is indicated as 3 horsepower at a speed of 60 miles per hour. From this diagram it will be seenthat the weights of cloth and truss are almost perfectly distributed and that the lumped Weights ofthe rudders and balancing planes are taken care Adirection of movement and with the axis of the device are balancediwithin the device.

In certain cases where the balloon tends to rise or fall more than desired, the dynamic tilt may be corrected by the forward rudder alone, so as to give a downwardly tending drift whenit is desired to make the balloon tend downward, or by the rear rudder alone, so as to give an upwardly tending drift when it'is desired to make the balloon tend upward, but any excessive drift tending to imbalance the symmetry of impingement and pressure of the air on the bow, 'i should be avoided. c

.In Fig. 12 I have shown the truss as eX- tending along the central' portion of the length of the gas bag only. In this case the conical bow and stern are not stayed by the truss, the sole support being afforded by the internal pressure of the gas acting as the compression member while the' walls of the envelop act as the tension member. -The propellers and rudders are nearer the center of the structure than inthe forms shown in the other figures.

In practice, itv is desirable to juse only as much internal gas pressure as necessary, and

I prefer to proportion the pressure 'to the speed. If the blower 1S -is of proper capacity and is actuated by the propeller shaft, speed and the propellers'stop.l

will fall when Fig. 9 diagrammatically indicates the ga bag as having the general contour of two concaved cones joined at the base by convex curves forming continuations of the curved line elements of the concaved cones', so that the contour ltaken lengthwise of the device consists of' a conca-ved curve, which will engage theair and displace the'same at a certain rate. The convex curvature corresponds to the decrement of the velocity in1-= parted by the deflecting surfaces, so that the air will be approximately in a state of rest ieee-,eee

by the time it reaches the central transverse plane 6l, 61 From this point, the air in a state ol' rest will acquire new velocity correr spending to the decrease in diameter oi the curve from 6l, lil rearwardly, and this inward velocity will be checked by taking eiect on the long tapered tail, which lwill ab sorb the energy of inward movement and leave the airv substantially in a state oi' rest after the passage of the tip 7l.

The modified form of forward delecting surfaces indicatedin Fig. 9 may be used in' connection with the features shown in any of the other Jfigures.

ln Fig. 13 I have shown seven dille-rent Iproportions of length and diameter which are well within the range of useful application for various special purposes or conditions, and any of these proportions may be applied for the gas bags shown in the other ligures and the deilecting surfaces may be true cones ormay be concaved longitudinally, as hereinbefore indicated. They may be used in connection with body portions curved on the radii indicated, or on other radii, or substantially similar shapes, and any oi the deiiecting suriaces indicated may be used for the bow of a balloon having any known or desired form ofoody portion or tail. In Fig. i3 the pitch of the surfaces and the ratios of diameters to total lengths are as follows: in the outer contour 8l, it is 1 to Il; in 82, it is l to 5;' in 83, it is l to 6'; in 84, it is l to 7; in A85, it is l to 8; in 8G, it is l to 9; in 87, it is l to l0. ln all these cases, the radius of longitudinal curvature oi the body portion is about equal to the diameter oi the gas bag, but this be *'greater or less in certain cases, as has been explained, .lt will be obvious that the principles whereby l determine the longitudinal contour of the point, body portion, and tail of my balloon are applicable where any or all of these portions have a cross-section whose outline 1s not a true circle. rlie varying angles of the surface and their radial distances from the airis, taken along any longitudinal radial may be given the required relation wits suicient degree of approximation, even 'where the cross-sectional outline is somewhat oval, polygonal, scalloped, or other shape, provided the rate ol variation or' said factors is ireserved for all longitudinal sections ncrilaal to each sin-face and `lel with-the axis, so to attain pres are results liereinbefore explained. in all cases, however, a circular or oval outline is preferable.

*Vliile l have scribed, and have pended claims cert struction, characterize my l' L Jfully shown and depointed out in the api novel features of conent, and operation which ation, il will be understood by tbc-se in the art that various omissions, submit-utilice, and changes in one forward and the other aft in. such relation, as to exert equal and opposite defiectin eiorts for the purpose describedq a 2. A motor balloon comprising an elongated envelop, in combination with a truss supporting the load' close to the envelop,

and balanced propellers located between the horizontal planes of said load and of the center of resistance respectively7 and havingr the unbalanced dynamic ei'lect oi' the propellers balanced by means of rudders which serve to create a dynamic couple operating in a vertical plane.

3. In a dirigible balloon, a gas bag comprising 'a longitudinally tapered envelop, a load carying truss, conforming in contour to the longitudinally contour of the envelop, propellers carried by said truss, and located between the horizontal plane of the load and the horizontal plane of the center oi? resistance of the balloon and a't or near the vertical plane oro the center of resistance oi the balloon, means for varying the speed oli' ehe propellers to balance their operative elicct and means for balancing the unbalanced dynamic eiiect of the propellers in a horizontal and vertical plane without causing the balloon to drift.

ln a dirigible balloon, a 7gas bag, comprising an envelop having a longitudinally ,tapered head in which the maximum pressure developed by the forward movement of the balloon is uniform over a large portion Y oi its surface, auxiliary means for supporting the tip of said head, means for maintaining an' internal pressure greater than the head pressure on said gas bag when the latter is trav ling ai, full speed, separate propellers adjacent opposite sides of said gas bag and means for balancing the thrust of said propellers.

5, ln a dirigible balloon, a gas bag comprising an envelop having a longitudinally tapered iead in which the maximum pressure developed by the forward movement of the balloon 1s uniform over a large portion' of its surface, auxiliary means for supporting the tip of said head, means for maintaining an internal pressure greater than the head pressure on said gas bag when the latter is traveling at fulll speed, a motor, separate propellers driven/thereby and disposed adjacent opposite sidesof said gas bag, and dili'erential gearing connecting said propellers.

In a `dirigible balloon, a gas bag com prising an envelop having a longitudinally tapered head iii which the maximum pressure developed by the forward movement of .the bal'n is uniform over a large'poi'tion of its surface, auxiliary means for supporting the tip of said head, means for main taining an internal pressure greater than the head pressure on said gas bag when the latter is' traveling at full speed, separate pro` pellers adjacent opposite sides of said gas bag, and means lfor vaiving Athe relative speeds of the propellers to oalance their operaive eiiects and insure point-on movenient.

7. .In a dirigible. balloon', a gas bag comprising an envelop having a pointed head in which the maximum pressure developed by the forward movement of the Vballoonis a' uniform over a large portion of its surface,

lauxiliary means for supporting the pointv of said head, means for maintaining an 11iternal pressure greater than the head pressure on said gas `bag when tlie latter is traveling at full speed, separate Propellers adjacent opposite sides of said gas bag, means for varying the relative speeds of the propcllers to balance their operative ellects, and

means for balancing the unbalanced dynamic efiectof ythe propellers in horizontal and balloon verticalA planes Without causing the to rift.

. In a dirigible balloon, a gas bag coin-i of the propellers to balance their operative effects, and a pair of rudders located one forward and the other aft in such relation to the structure as toprodueeequal and opposite turning effects.

Signed at New York city, in the county of New York and State of New York this seventeenth day o f April, A. D. 1908.

APETER COOPER HEWITT.

Witnesses:A

Iizvme M. WRIGHT, HUGO CENTEWALL. 

